An object-oriented programming language (OOPL) typically defines not only the data type of a data structure, but also the types of functions that can be applied to the data structure. In essence, the data structure becomes an object that includes both data and functions. During execution of an OOPL program, access to an object's functionality occurs by calling its methods and accessing its properties, events, and/or fields.
In an OOPL environment, objects are often divided into classes wherein objects that are an instance of the same class share some common property or properties (e.g., methods and/or instance variables). Relationships between classes form a class hierarchy, also referred to herein as an object hierarchy. Through this hierarchy, objects can inherit characteristics from other classes.
In object-oriented programming, the terms “Virtual Machine” (VM) and “Runtime Engine” (RE) have recently become associated with software that executes code on a processor or a hardware platform. In the description presented herein, the term “RE” includes VM. A RE often forms part of a larger system or framework that allows a programmer to develop an application for a variety of users in a platform independent manner. For a programmer, the application development process usually involves selecting a framework, coding in an OOPL associated with that framework, and compiling the code using framework capabilities. The resulting platform-independent, compiled code is then made available to users, usually as an executable file and typically in a binary format. Upon receipt of an executable file, a user can execute the application on a RE associated with the selected framework.
Traditional frameworks, such as the JAVA™ language framework (Sun Microsystems, Inc., Palo Alto, Calif.), were developed initially for use with a single OOPL (i.e., monolithic at the programming language level); however, a recently developed framework, .NET™ framework (Microsoft Corporation, Redmond, Wash.), allows programmers to code in a variety of OOPLs. This multi-OOPL framework is centered around a single compiled “intermediate” language having a virtual object system (VOS). As a result, the object hierarchy and the nature of the compiled code differ between the JAVA™ language framework and the .NET™ framework.
For the discussion presented herein, the term “bytecode” is generally associated with a first framework and the term “intermediate language code” or “IL code” is associated with a second framework, typically capable of compiling a variety of programming languages. In a typical framework, the framework RE compiles code to platform-specific or “native” machine. This second compilation produces an executable native machine code. Throughout the following description, a distinction is drawn between the first compilation process (which compiles a programming language code to bytecode or an intermediate language code) and the second compilation process (which compiles, for example, a bytecode or an intermediate language code to native machine code/instructions). In general, a “compiled code” (or “compiled codes”) refers to the result of the first compilation process.
To enhance portability of programming languages and compiled codes, there is a need for methods and/or devices that can perform the following acts: (i) compile a programming language code associated with a first framework (e.g., a bytecode framework) to a compiled code associated with a second framework (e.g., an IL code framework); and (ii) convert a compiled code associated with a first framework (e.g., a bytecode framework) to a compiled code associated with a second framework (e.g., an IL code framework). Such methods and/or devices should account for differences in class loading and perform without substantially compromising the original programmer's intent.